Hydrostatic control for pumps



Nov. 15, 1949 L. F. BERNHARDT 2,438,506

HYDROSTATIC CONTROL FOR PUMPS Filed Aug. 28, 1948 ltigrnej Patented Nov. 15, 1949 HYDROSTATIC CONTROL FOR PUMPS Lee F. Bernhardt, Fort Wayne, Ind., assignor to American Brass and Aluminum Foundry, Incorporated, a corporation of Indiana Application August 28, 1948, Serial No. 46,680

4 Claims. (Cl. 103-25) This invention relates to improvements in a hydrostatic control for pumps 01 the motordriven type adapted automatically to cause opercally activated upon accumulation of liquid in the sump and which is thrown out of action automatically when the accumulation shall have been substantially reduced to a predetermined low level.

And another object of the invention is to provide a mechanism for automatically operating an electric switch that controls the motor for a pump, dependent upon the rise and fall of the liquid level in a sump with which the pump is connected.

Other objects and advantages of the invention appear in the following description.

An illustrative embodiment of the invention is shown in the accompanying drawings, in which- Fig. 1 is a side elevationa1 view of a structure in which the invention is incorporated, parts being broken away;

Fig. 2 is a fragmentary side elevational view including an electric switch and activating mechanism therefor in normal open position, parts being shown in section;

Fig. 3 is a fragmentary side Velevational view, partl in section, of the switch and activating mechanism therefor, shown as when the switch is initially closed;

Fig. 4 is a similar fragmentary side elevational view of the switch and operating mechanism therefor, including the hydrostatic pressure tube, the switch operating mechanism being in fully sustained switch closing position; and

Fig. 5 is another fragmentary side elevational view, partly in section, showing a pump in its housing, including the hydrostatic pressure tube connected therewith.

The illustrative embodiment of the invention consists of a pump mechanism for a sump, a motor for activating the pump, a switch for controlling the electric circuit for the motor, and a means for initially closing the switch automatically dependent upon the rise of liquid in the sump and for opening the switch automatically when the level of liquid in the sump shall have been lowered by action of the pump to a predetermined level in the sump.

In the construction shown there is provided a P p preferably 0! a common centrifugal type, enclosed in a housing I provided with a suction intake I covered by a screen 6', there being a tubular post 8 extending upwardly from the housing and upon .the top of which is supported a motor 9 connected with the pump by a driveshaft ill extending concentrically up through. the post. Supported on the housing is a stand-pipe ii, the lower end of which is open to receive flow of liquid from the sump (not shown) in which the housing I is positioned, and has secured in the lower end a choke-ring l2, having a bore of selected diameter, by which'is predetermined the rate of flow of fluid into and out from the stand-pipe, the flow of liquid being occasioned by accumulation of the liquid in the sump or its withdrawal therefrom by action of the pump.

On the top of the stand-pipe is mounted an encasement IS in which is disposed an electric switch l4 provided with an operating stem l5 by movement of which the switch is closed or opened accordingly as activated. Within the encasement is arranged a movable plate l8 hinged at one end as indicated by H, or otherwise guided for vertical movement. The operating stem l5 for the switch has contact with the upper face of the movable plate and is activated thereby so that the switch is closed when the plate is raised, and opens when the plate resumes its normal position. On the bottom of the encasement beneath the plate is is secured an elastic diaphragm ill, by which said plate is activated. A portion of 7 said diaphragm overlies and closes the upper end of the stand pipe H, and another portion of .the diaphragm overlies and closes the upper end of a hydrostatic tube IS, the lower end of which tube is connected with and has communication with the pump housing I. The arrangement is such that when air pressure is raised in .the standoipe due o flow or liquid from the sump, that portion of the diaphragm overlying the standpipe is bulged upwardly, causing the plate IE to bear against the stem l5, resulting in closing of the switch and consequent operation of the motor and the pump connected therewith, whereupon, the accumulation of liquid in the sump is impelled by action of the pump from the housing 1 out through a discharge pipe 20 for final disposal.

During operation oi the pump the liquid pressure that occurs in the housing causes another portion of the diaphragm that overlies the tube ll, to rise and bear against the plate It, thereby sustaining the switch in closed position and consequent continuation of operation of the motor and the pump, and removal of liquid from the sump. As the liquid level in the stand-pipe recedes, that,portion of the diaphragm overlying the stand-pipe, collapses to normal position while the plate I is sustained in switch closing position due to hydrostatic pressure in the tube is against that portion of the diaphragm overlying the top thereof. In this manner operation the motor and the pump continues until the level of the liquid in the sump recedes to such low level that air is admitted into the pump housing resulting in exhaustion of the hydrostatic pressure in the tube It, and collapse of the overlying diaphragm thus permitting the plate It to resume its normal position and consequent reopening of the switch and stopping of the pump.

Whenever the sump becomes refilled, pressure within the stand-pipe occasioned by the rise oif the liquid level therein causes automatic closing of the switch and resumption of the pumping operation followed by automatic closing of the switch and, consequent stoppage of the pump, without the attendance of an operative.

The switch I3 is connected in the motor circuit in the usual manner as indicated at II, and the motor is energized by current supplied by conductors 22 that are connected with a suitable source 0! energy (not shown). By this arrangement the pump is operated dependent upon closing of the switch when the sump becomes filled with liquid, which, operation is protracted until the sump is substantially emptied of its contents, whereupon the switch is permitted to return to its open position.

An important feature of the invention is that the switch is initially closed due to influx of liquid into the sump, followed by operation of the pump and development of hydrostatic pressure in the tube i9, causing the switch to be sustained in closed position and consequent continued operatlon of the pump until the sump is emptied and pressure in the tube is is relieved, thus allowing the switch to re-open. In this manner the operations of initially closing and subsequently reopening the switch are independent of each other, the closing and re-opening operations being sequential and respectively incidental to filling and emptying of the sump.

Variations from the particular construction above disclosed may be resorted to by the exercise of skill in the art, without departure from the spirit or scope of the invention.

What I claim is:

1. An automatically operated apparatus for controlling a motor driven pump, said apparatus consisting of a switch connected in the energizing circuit for the motor, a movable plate engageable with the operating stem of said switch, a diaphragm operatively engaging said plate to activate it, a stand-pipe the lower end of which is open and its upper, end closed by said diaphragm, a secondary pipe connected at one end thereof with the'pump housing, its upper end being closed by said diaphragm apart from the stand-pipe, and means for energizing the pump motor, so that when the stand-pipe and pump housing are submerged in liquid, pressure in the stand-pipe is occasioned thereby, accompanied by closing of the switch, sequential operation of the pump and development of pressure by said pump whereby the switch is sustained in its closed po- 4 sition and consequent continued operation of the pump until pressure in said secondary pipe is exhausted when the liquid being pumped recedes to the level of the suction intake of the pump.

2. An automatically operated pumping mechanism including a motor-driven pump, provided with an energizing circuit for the motor, a switch connected in the motor, circuit, a stand-pipe, open at its lower end and having supported connection with the switch, an auxiliary pipe connected with th pump housing, a diaphragm closing the upare submerged and pressure is raised in the standpipe upon submergence, and pressure is devel oped in said auxiliary pipe upon operation or the 3. A pumping mechanism in which is included a pump provided with an activating motor therefor, a switch controlling circuit for said motor having a casing enclosing it, a stand-pipe the bottom of which is open and the top of which extends into said casing, another pipe connecting the pump housing and said casing, and 9. diaphragm individually closing the stand-pipe and said other pipe having means in operative connec-'- tion therewith engageable with the stem or said switch to activate the switch, the parts being ar, ranged so that, when the pump is submerged, liquid enters the stand-pipe causing pressure therein, movement of the diaphragm, closing of the switch, consequent energizing of the motor and activation of the pump, whereupon pressure is raised in said other pipe causing movement of said diaphragm whereby the switch is maintained in closed position until pressure in said stand-pipe and said other pipe is relieved.

4. A sump pump having a motor-driven pump, a switch controlling the circuit for the pump motor, a stand-pipe open at its bottom, another pipe connected with and extending upwardly from the pump housing, and a diaphragm indi-v vidually closing said stand-pipe and said other pipe at the upper ends thereof and having means in connection therewith engageable with the stern of said switch, so that when the pump becomes submerged by influx of liquid into the sump the liquid rises in the stand-pipe causing movement of the diaphragm, closing of the switch and consequent operation of the pump, whereupon pres--v sure is created in said other pipe causing a sec-1 ondary movement of the diaphragm by which the switch is sustained in closed position and con-, sequent continuation of the pump operation until pressure in said other pipe is relieved. I

- LEE F. BERNHARDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Collin Jan. 8, 1935' 

